1. Field of the Invention
The invention relates in general to a memory and a manufacturing method and a programming method thereof, and more particularly to a magnetic random access memory (MRAM) and a manufacturing method and a programming method thereof.
2. Description of the Related Art
Along with the wide application of consumer electronic products, the requirements of the processing speed and the capacity of the storing digital data is higher and higher. The memory plays an important role in the consumer electronic products. Consumers develop higher and higher requirements of the memory including the power consumption, the cost, read/write speed and the erasing times. Therefore, several new invention memories are presented to fit the needs of different market segmentations with an aim to break through the current memory restrictions and become the mainstream technology for the new generation memory.
Examples of current memories include dynamic random access memory (DRAM), flash memory (Flash Memory), static random access memory (SRAM) and magnetic random access memory (MRAM). The magnetic random access memory (MRAM) is a new invention non-volatile memory, having the same non-volatile characteristics as that of the Flash memory. Moreover, the magnetic random access memory (MRAM) is comparable to the static random access memory (SRAM) in terms of read/write speed. The unit memory area of the magnetic random access memory (MRAM) is further comparable to that of the dynamic random access memory (DRAM). Therefore, the magnetic random access memory has been accepted as a new generation memory with high potentials.
In the magnetic random access memory (MRAM), data are programmed through the spin-transferring of current or electron current. When the magnetic random access memory has a large resistance, the magnetic random access memory is defined as “0”. To the contrary, when the magnetic random access memory has a small resistance, the magnetic random access memory is defined as “1”. That is, a conventional magnetic random access memory can store 1-bit data. If the to-be-programmed data has 4 bits, the data of “0” or “1” needs to be programmed to four conventional magnetic random access memories. As the electronic products are designed to meet the requirements of lightweight, slimness, compactness, and speed, conventional magnetic random access memory can only program 1-bit data, not only occupying a larger volume but also further reducing the programming speed. Therefore, how to effectively reduce the volume and improve the programming speed of the magnetic random access memory has become an imminent issue to be resolved.